<div id="map"></div>
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        container: 'map',
        style: 'mapbox://styles/mapbox/outdoors-v11',
        center: [-121.403732, 40.492392],
        zoom: 10
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    map.on('load', function() {
        map.addSource('national-park', {
            'type': 'geojson',
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        map.addLayer({
            'id': 'park-boundary',
            'type': 'fill',
            'source': 'national-park',
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            },
            'filter': ['==', '$type', 'Polygon']
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            'id': 'park-volcanoes',
            'type': 'circle',
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                'circle-color': '#B42222'
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